Novak Djokovic will be spurred on by the conviction that his best days are
still ahead of him as he comes to terms with losing another grand slam final.

The Serbian has been phenomenally consistent at the slams, ­reaching 14 consecutive semi-finals and the final at 10 of the last 13 major tournaments. But, having won five of his first seven finals, he has now lost four of the last five, with Rafael Nadal confirming it is he who is now the best player in the world with a 6-2, 3-6, 6-4, 6-1 victory at the US Open.

Asked how he can turn disappointment into motivation, Djokovic said with a smile: “I have to. It’s part of my life. Many times you fall as an athlete, and you have to learn the lesson and keep on going, keep on fighting, keep on improving. That’s what we are here for.

“I’m still 26, and I believe the best time for my career is about to come. As long as I believe it, the fire of the love towards the game is inside of me. And as long as that’s present, as long as I feel it, I’m going to play this sport with all my heart, as I did in the last 10 years.”

It has been another successful season for Djokovic, but the edge he had in 2012 and especially 2011 is no longer there. The Serbian has not won a title since April and has suffered several painful losses, especially to Nadal in the French Open semi-finals and Andy Murray in the Wimbledon final.

Howver, he feels there are plenty of positives to take from his fortnight in New York. “I was playing well throughout the whole two weeks, and I can be happy because it was different from the hard-court tournaments prior to the US Open. I felt more mentally present and I was going for my shots. I wish I won at least one more grand slam title [this year]. All the matches I lost, even the French Open, I had that match.”

Djokovic will hang on to his world No 1 ranking for now but he knows it is inevitable that Nadal will overtake him, probably next month when they head to Asia. “He won so much this year,” Djokovic said. “Year to year he’s far, far ahead, and he has much more chance to end up as number one. There are still tournaments to go. So we’ll see. I’ll just try to prepare myself for China.”

Nadal’s victory was all the more incredible for the fact that last year he watched the final on television at home in Majorca, laid up with knee trouble that would keep him out for seven months.

Many people wondered whether he would ever challenge again for titles on hard courts - the most punishing surface on the body. Not only has he challenged, he has swept all before him, winning all 22 matches on hard courts and four titles.

Nadal never doubted he could again play at the level that brought him a first US Open title in 2010, so long as his knees allowed him.

“The doubt is if I am healthy or not,” he said. “With seven months out, I was sure that I would not forget how to play tennis. If you are healthy, if you have been in the top positions for nine years already, why would you not have the chance to be back there?”

Nadal’s win took him to 13 grand slam titles, one behind Pete Sampras and four adrift of Roger Federer’s all-time record. That tally now appears well within touching distance, and Djokovic said: “Thirteen grand slams for a guy who is 27 years old is incredible. He still has a lot of years to play.”

Theoretically, he could equal Federer in New York next year, but Nadal believes the level of the game makes it impossible for any player to win a calendar Grand Slam – one of the only major honours he has not yet achieved. He said: “We will see, but today the best players are there all the time, so to win a tournament like this you have to win against Roger, against David [Ferrer], against Andy, against Novak. When your level is a little bit lower, you will lose against these players 100 per cent.

“My goal is to keep having chances to play, to enjoy, and to be healthy. That’s the most important thing.”